A model is proposed to account for elutriation and attrition based on the assumption that the generation of fine particles by means of attrition depends on the percentage of the mass of fine particles in the bed. Elutriation rate constants and attrition rates were evaluated for various types of particles (TiO2, CaCO3). A decrease in the elutriation rate constant and in the attrition rate of the model was observed when the fines loaded in the bed increased. The decrease in the elutriation and attrition rates was significant when the powder cohesiveness diminished. The effect of the initial mass of fine particles on fluidized bed elutriation is also discussed.